Related papers: A 4th generation scenario
Taking the MSSM as an effective low-energy theory, with a cut-off scale of a few TeV, can make significant modifications to the predictions concerning the Higgs and stop sectors. We investigate the consequences of such a scenario for…
Recent studies of precision electroweak observables have led to the conclusion that a fourth generation is highly constrained. However, we point out that a long-lived fourth generation can reopen a large portion of the parameter space. In…
We investigate the effect of introducing a sequential generation of chiral fermions in the Higgs Triplet Model with nontrivial mixing between the doublet and triplet Higgs. We use the available LHC data for Higgs boson production and decay…
Next-to-MSSM is a viable model which is equipped with two features suited for electroweak baryogensis (EWBG): first-order phase transition not restricted by the Higgs spectrum and tree-level CP violation in the Higgs sector free from the…
The new SM-like Higgs boson discovered recently at the LHC, with mass $m_h \simeq$ 125 GeV, as well as the direct LHC bounds on the mass of superpartners, which are entering into the TeV range, suggest that the minimal surviving…
We propose a new electroweak baryogenesis scenario in high-scale supersymmetric (SUSY) models. We consider a singlet extension of the minimal SUSY standard model introducing additional vector-like multiplets. We show that the strongly…
We describe a nonstandard proposal for baryogenesis in models with a low (O(10-100)TeV) fundamental scale. The scenario has Standard Model field content and enhanced baryon number violating operators deriving from time-dependent fermion…
We show that, if a fourth generation is discovered at the Tevatron or LHC, one could study CP violation in b' \to s decays. Asymmetries could reach 30% for b'\to sZ for m_{b'} \lesssim 350 GeV, while it could be greater than 50% for b'\to…
We explore the possibility of a fourth generation in the gauge-coupling-unified, minimal supersymmetric (MSSM) framework. We find that a sequential fourth generation (with a heavy neutrino $\nu'$) can still fit, surviving all present…
We study the observability for a Higgs boson at upgraded Tevatron via the modes gg->h->ZZ->4l (l=e,mu). We find that the signal can be observed at an integrated luminosity of 30 fb^(-1) if the fourth SM family exists.
We investigate the possibility of incorporating a chiral fourth generation into a GUT model. We find that in order to do so, precision fits to electroweak observables demand the introduction of light (< M_Z) supersymmetric particles. This…
Recent results from the Tevatron are reported on Higgs boson searches in models beyond the standard model (SM). The models include fermiophobic Higgs bosons, the extension of the SM to a fourth generation of fermions, supersymmetric…
We analyse the impact of LHC and Tevatron Higgs data on the viability of the Standard Model with a sequential fourth generation (SM4), assuming Dirac neutrinos and a Higgs mass of 125 GeV. To this end we perform a combined fit to the signal…
The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. The current limits from the Tevatron and the prospective sensitivities at the LHC are often interpreted in specific MSSM scenarios. For…
We reanalyze constraints on the mass spectrum of the chiral fourth generation fermions and the Higgs bosons for the standard model (SM4) and the two Higgs doublet model (THDM). We find that the Higgs mass in the SM4 should be larger than…
The possibility of incorporating a chiral fourth generation into a SUSY-GUT is investigated. Precision fits to electroweak observables require us to introduce light supersymmetric particles, with masses less than mZ. These particles might…
We show that the 4-Dimensional Composite Higgs Model (4DCHM) could provide an even better explanation than the Standard Model (SM) of the current Large Hadron Collider (LHC) data pointing to the discovery of a neutral Higgs boson. The full…
We demonstrate that the observed baryon asymmetry in the Universe can be accommodated in the extended Standard Model with sequential fourth generation fermions (SM4). We first construct the dimension-6 effective operators of the type…
Using the experimental result on b\to s\gamma and theoretical result on b\to sg, a four -generation SM is analysed to constrain the rephasing-invariant combinations of the CKM matrix and masses of the fourth generation quarks.
Limits are derived on models with extended Higgs sectors, including the Minimal Supersymmetric Standard Model (MSSM), by exploiting the data on $\tau^+ \tau^- + $ 2 jets final states, used by the CDF collaboration to place limits on third…